Re thinking Chemistry (identifying ions) with Computational Thinking

When I first ‘meet’ computational thinking about 18 months ago at a presentation by Lisa Anne Floyd, I was hooked!! I wanted to dive straight in, and as such my first few attempts at using computational thinking frameworks kind of fizzled with my classes. (you can see my earlier post on computational thinking HERE) It has taken a while for my understanding to percolate and over the course of the last 18 months I’ve done some reading, some talking (thanks Nikkie and Kevin mostly) and some teaching and come to realise that you don’t need to do all the parts of computational thinking at once. For example, as part of the yr 7 digital technologies course I am teaching, we focus on algorithms and data representation (so a little pattern recognition, we might need to make this more explicit) with very little on decomposition and abstraction. As the new digital technology curriculum in New Zealand has a focus on computational thinking, I’ve been wondering how I could incorporate this more into my science classes. I was original thinking solely of juniors, at mostly around some add in activities such as hacking STEM lessons, or some maker space activities, or using MinecraftEDU. But have decided to be brave and have a go with my Level 2 NCEA Chemistry class with the AS 91162 identifying ions in solution standard.

I’ve decided this after learning a little bit more about computational thinking. some of this comes from being in digital technology class with Kevin teaching the yr 7’s. In my own learning, some of the resources I used included this great wee course aimed at kids via the bbc bite size site. Then there is the Computational Thinking course on the microsoft educator community, which had a link to this blog piece written by Janette Wing (and a link to the original viewpoint article, which is 10 year old)

There were also some videos I watched, while a little ‘cheesey’ this was a favourite… the idea of sorting puzzle pieces appealed to me, I always sort the edges first, then colours or a pattern.

But what it took for me to finally get my head to get to this point was a conversation with Nikkie about teaching kids to read, and using pattern recognition to identify words. The next night, I was with my Mr 5 as he read his story book and he read in his book look, looked and looking (On a seperate topic, my goodness kids books are insanely dull at times…).

I had an mini epiphany. It was simply that simple, and I had been making it too hard in my head. Not everything needed to be done at once.

Usually, I teach this by starting out with the solubility rules which make up a flow chart the students can follow during the internal to identify the ions. Depending on time, we might have a play with the solutions and see what patterns we can find, and what ions form precipitates with others. Generally though, I rush this step, so I can spend more time on balancing ionic equations and the justifications around the steps which students require for excellence.

Students get a flow chart like this one in the assessment to help them identify the ions in different solutions – this is for cations, and there is another for anions.

Because I had finally gotten my head around (decomposed perhaps) the idea that I didn’t need to do ALL of computational thinking to teach computational thinking, what could I include?

The obvious one is algorithms – as there is already a flow chart in place.

But I wondered why I couldn’t let the students design there own flowchart…. maybe not to use in the assessment because I’m not sure it would pass moderation…. as a way of learning how to use a pattern to make an algorithm. And exploring the patterns of solubility (for time I might get a group to do everything with Cl-, and another group to do everything with I-, and then compare notes) we can do a fairly good job of pattern recognition. This group activity might also fit nicely into knowledge building and collaboration, and hits all the nature of Science stuff.

I was talking this through with Kevin and of course he said – well, you could make some sort of scratch program based on the flowchart – a series of yes/no questions to find the ion. So I will put the option to the students – there are a couple who are also in Kevin’s Robotics class – that if they want to make a program, they can. Again, I’m not sure they would be able to use this in the assessment, but if it works, I might find out more about this for next year…..

So I am starting smaller this time, and aiming for pattern recognition and algorithmic thinking. Students will work in groups over a lesson or two to identify which of the required ions for their assessment react with what. We will compare data and look for trends (and then compare to the solubility rules). Then design a flow chart to determine for an unknown – which might need some iteration along the way. And of course, as they are working on this, I’ll throw in that they have to write the correct balanced ionic equations for precipitates and for the complex ions formed. I’m really hoping that by asking the students to write their own flowcharts, they will ace the part of the assessment where they need to justify their ‘choice’ of ion, as they should develop a thorough understanding of the idea behind it.

I’ll also give the option of the scratch program. And if time allows (it probably won’t…. sigh) I would like to go more into the pattern recognition of why some salts are more soluble than others, linking back to atomic and ionic structures and energy….. oh the places we could go